A person who works with gold is called a goldsmith.
A person who works with precious metals is typically called a "jeweler" or a "metalsmith." These professionals are skilled in crafting jewelry and other items using materials like gold, silver, and platinum.
A person who works at a dry cleaning establishment is typically called a dry cleaner or a dry cleaning specialist.
Edmond Locard was the first person to apply principles of forensic science to a working crime laboratory. He applied what is called the Locard's exchange principle to a working crime laboratory.
A person that makes make up works for the cosmetic Industry. They are considered to be chemist since the formulate the composition of the make up.
Scientist
It's depend on what that person is working on. But I would call it a Laboratorist
Tech Person
a slave
Employee
someone who works for a business
hydrologist
moofer
A Chronogist
A mathematician
A BarMan
Railroader